标题： ${\it Ab \: initio}$密度泛函研究13原子铜和银团簇 显示英文标题

标题： ${\it Ab \: initio}$ density-functional studies of 13-atom Cu and Ag clusters

摘要： 13原子铜和银团簇的假定基态结构通过基于密度泛函理论（DFT）的${\it ab \: initio}$分子动力学（AIMD）模拟进行了研究。 在AIMD轨迹中收集的一组低能构型，并优化到最近的局部最小能构型，进行了研究。 结果分析表明，存在低对称双层结构，作为铜$_{13}$和银$_{13}$团簇的假定基态结构的强候选者。 这些双层结构与弯曲双平面（BBP）构型显著不同，并且比之前其他人提出的构型在能量上更有利，大约0.4$-$0.5 eV。 我们的研究表明，对于给定的交换-相关泛函，所得假定全局最小构型的结构基本上独立于计算中使用的基函数的性质（即平面波与赝原子轨道）。 从基于平面波的DFT计算得到的结构配置显示，铜和银原子的第一壳层比从局域基函数得到的结构更紧密或更密集。 本文展示了我们的结果与最近全势DFT模拟的比较。 显示英文摘要

摘要： The putative ground-state structures of 13-atom Cu and Ag clusters have been studied using ${\it ab \: initio}$ molecular-dynamics (AIMD) simulations based on the density-functional theory (DFT). An ensemble of low-energy configurations, collected along the AIMD trajectory and optimized to nearest local minimum-energy configurations, were studied. An analysis of the results indicates the existence of low-symmetric bilayer structures as strong candidates for the putative ground-state structure of Cu$_{13}$ and Ag$_{13}$ clusters. These bilayer structures are markedly different from a buckled bi-planar (BBP) configuration and energetically favorable, by about 0.4$-$0.5 eV, than the latter proposed earlier by others. Our study reveals that the structure of the resulting putative global-minimum configuration is essentially independent of the nature of basis functions (i.e., plane waves versus pseudoatomic orbitals) employed in the calculations, for a given exchange-correlation functional. The structural configurations obtained from plane-wave-based DFT calculations show a slightly tighter or dense first-shell of Cu and Ag atoms than those from local-basis functions. A comparison of our results with recent full-potential DFT simulations is presented.